On the one hand, I am now testing a platform with 2 processors Istanbul 2435 @ 2.6GHz which are connected on the mainboard. This amounts to a total of 12 cores. On the other hand, I running the same numerical simulation in a computational node with 2 processors Nehalem E5520 @ 2.27GHz and Shanghai 8382 @ 2.6GHz. The latter amounts to 8 cores.

When running a parallel icoFoam case I found that the performance of Nehalem is much better than Istanbul. Do you know how could I optimize OpenFOAM for Istanbul?